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2010年我的一篇文章－－氧化锌缺陷发光机制与调控
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缺陷对氧化锌的光学、光电子学性能有着非常显著的影响。数十年来，ZnO可见发光的缺陷机制一直存在争议，缺乏统一的理论解释。
近年来，我们发展了具有局域瞬态极端条件的液相激光烧方法，并进行纳米颗粒的独特微结构相关的物性研究。在此基础上，获得了具有稳定较强蓝色发光的氧化锌纳米颗粒，进行了对缺陷发光机制的探索。一方面，研究了蓝色发光对激发波长依赖性。发现：1，蓝色发光存在几个固定的择优发射能量点；2，蓝色发光到绿色发光的转变，不是连续移动而是此消彼长的过程；3，蓝色发光的激发谱可以延伸到可见光波段，相应激发能量明显小于带隙宽度，并存在一系列子峰。另一方面，对相关缺陷进行了电子顺磁共振和正电子湮灭的研究。观察到间隙锌、空位氧、间隙锌复合缺陷、间隙氢在一定条件下的共存；随着蓝色发光到绿色发光的转换，间隙锌和空位氧在EPR谱中存在强烈相关的变化。此外，通过更细致的微结构控制，可见发光获得了一定称度上的调控。
该工作将有助于氧化锌可见发光的最终确立，推动相关基础研究与应用；同时也指出，相对于通常所注意的形貌、尺寸等，纳米材料的微结构控制对其性能具有及其重要的意义。相关论文发表在Adv. Funct. Mater. 2010, 20.561-572.上。该工作得到了国家自然科学基金的资助。
Blue Luminescence of ZnO Nanoparticles Based on Non-Equilibrium Processes: Defect Origins and Emission Controls
文章的PDF文件
By Haibo Zeng,* Guotao Duan, Yue Li, Shikuan Yang, Xiaoxia Xu, and
Weiping Cai
Weiping Cai
High concentrations of defects are introduced into nanoscale ZnO through
non-equilibrium processes and resultant blue emissions are comprehensively
analyzed, focusing on defect origins and broad controls. Some ZnO
nanoparticles exhibit very strong blue emissions, the intensity of which first
increase and then decrease with annealing. These visible emissions exhibit
strong and interesting excitation dependences: 1) the optimal excitation
energy for blue emissions is near the bandgap energy, but the effective
excitation can obviously be lower, even 420nm (2.95 eV<Eg¼3.26 eV); in
contrast, green emissions can be excited only by energies larger than the
bandgap energy; and, 2) there are several fixed emitting wavelengths at 415,
440, 455 and 488nm in the blue wave band, which exhibit considerable
stability in different excitation and annealing conditions. Mechanisms for blue
emissions from ZnO are proposed with interstitial-zinc-related defect levels
as initial states. EPR spectra reveal the predominance of interstitial zinc in asprepared
samples, and the evolutions of coexisting interstitial zinc and
oxygen vacancies with annealing. Furthermore, good controllability of visible
emissions is achieved, including the co-emission of blue and green emissions
and peak adjustment from blue to yellow.
non-equilibrium processes and resultant blue emissions are comprehensively
analyzed, focusing on defect origins and broad controls. Some ZnO
nanoparticles exhibit very strong blue emissions, the intensity of which first
increase and then decrease with annealing. These visible emissions exhibit
strong and interesting excitation dependences: 1) the optimal excitation
energy for blue emissions is near the bandgap energy, but the effective
excitation can obviously be lower, even 420nm (2.95 eV<Eg¼3.26 eV); in
contrast, green emissions can be excited only by energies larger than the
bandgap energy; and, 2) there are several fixed emitting wavelengths at 415,
440, 455 and 488nm in the blue wave band, which exhibit considerable
stability in different excitation and annealing conditions. Mechanisms for blue
emissions from ZnO are proposed with interstitial-zinc-related defect levels
as initial states. EPR spectra reveal the predominance of interstitial zinc in asprepared
samples, and the evolutions of coexisting interstitial zinc and
oxygen vacancies with annealing. Furthermore, good controllability of visible
emissions is achieved, including the co-emission of blue and green emissions
and peak adjustment from blue to yellow.
氧化锌纳米颗粒的发光与激发光谱
建议的缺陷发光机制、可见发光调控
发表后记：
对这项工作与这篇文章颇有些感慨。
从工作的开始到发表历时是我至今最长的。这是在我博士工作基础上的继续，留所2年主要精力就花这上面了。当然，还有部分数据没发表。这是个科学问题探索型的基础研究，历程如下。随着对领域认识的不断加深，逐渐对领域内有哪些主要问题、研究状况有了自己的认识。慢慢的，有了解决其中一个（其实就目前潮流而言，是既不新也不热了）的冲动。随后就是独立设计方案，实施试验，进行分析。期间，少不了再学习、再调整、再实施。再后来，数据逐渐积累多了，就自然进入到思考与分析方面，体会数据，体会内涵，体会关联方面，真是所谓殚精竭虑！最后是，逐渐形成了一点自己的观点，就有加入了求证－再试验－分析的循环中。
相反，最后发表到好像没什么故事。本准备好被AFM拒稿后转投物理类IF稍低的杂志的，没想到很快收到的意见都较好，直接接受了。接受后，好像也没什么太高兴的。
自己评价：这是我至今比较好的工作，历史可能会证明观点是错误的，不过我也没什么遗憾的！
这个过程增加了我对科研，对科研中的自己的认识：
1， 认真做点科研，真是不容易！（反之，我的有些文章并没有这么辛苦）
2， 如果能认真做点科研，也不错啊。
3， 要边做边学边提高。
文章的PDF文件
https://m.sciencenet.cn/blog-2425-296781.html
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